Mechanism of Surface Forming in Grinding Machinable Glass Ceramics

The mechanism of surface forming and surface roughness are studied in grinding process of machinable glass ceramics by the grinding experiment which is conducted on the MK9025 A curve grinder. The results indicate that there are three forms when grinding ceramic materials, such as ductile removal, ductile brittle removal and brittle removal. The undeformed chip thickness model of machinable ceramics is improved by the correlation coefficient of brittle materials Mr. Also, the ductile-ductile brittle and ductile brittle-brittle critical grinding depth models are developed by putting forward the ductile domain coefficient η0 and the ductile brittle domain coefficient η1. The composite grinding factor Q is proposed according to the single factor experiment of machinable glass ceramics in grinding and the model of surface roughness is established based on the above undeformed chip thickness model and two critical grinding depth models. The relationship is obtained between surface roughness and the composite grinding factor. The accuracy of model is tested with the standard deviation, and the results of orthogonal experiments indicate that the experimental value of surface roughness of machinable glass ceramics is in agreement with the theoretical value of the model of surface roughness.